Pyridine-methylsulfinyl compounds act as proton pump inhibitors and are used in the treatment of pathologies related to an increase in gastric secretion. Examples of these compounds, known as “prazoles”, are omeprazole, esomeprazole, pantoprazole, rabeprazole, lansoprazole, tenatoprazole and hydroxymeprazole.
The synthesis of these products is substantially carried out following the scheme reported below, wherein R1-R7 and Q are for example as herein defined.

It is evident that such synthesis requires a number of complex steps.
WO 98/40378 discloses the synthesis of “prazoles” by reduction of the respective N-oxides. The exemplified reducing agents for carrying out this reaction are dangerous to handle (for example Ni-Raney), sometimes incompatible with the substrate to be reduced (for example Ni-Raney/H2 or Ru/H2), or difficulty available on the market (for example bis-thiomorpholine) and expensive. Furthermore, the synthesis of the intermediate N-oxide reported therein involves a complex, time-consuming process. This makes the process incompatible with the requirements for the industrial production and evidences the need for improved synthetic methods.